The River Oykel (Scottish Gaelic: Òiceall / Abhainn Òicill, pronounced [au.ɪɲ ɤçɡ̊ʲɪɫ̪]) is a major river in northern Scotland that is famous for its salmon fishing. It rises on Ben More Assynt, a few miles from Ullapool on the west coast of Scotland, and drains into the North Sea via the Kyle of Sutherland. Traditionally it has marked the boundary between Ross to the south and Sutherland to the north.